Improvement in saw-mill head-blocks



@with tant atrat @Hina DARIUS -PARKHURST, OF ST. LOUIS, MISSOURI.

v Letters Patent No. 69,122, dated September 24, 1867.

IMPROVEMENT IN SAW-MILL HEAD-BLOCKS.

dlge rlgtmh referat tu in tiges trttat atent mit matin-g mtl nt tigesmut.

TO ALL WHOM I'I MAY GONCERN:

Be it known that I, DARIUs PARKHURST, of the city and county of St.Louis, and State of Missouri, have invented a new and useful Improvementin Saw-Mill Head-Blocks and Carriages; and I do herebydeclare that thefollowing is a full and clear description thereof, reference being hadto the accompanying drawings, and to the letters ofreference markedthereon.

'.Ihe object of this invention is to construct the headblocks of asaw-mill in such a manner that either one or both of them may be movedat the same time by means of a single actuating lever, thus giving tothat class of hcad-blocks known as self-acting the increased advantageof being moved further on one end than on the other, and thenalternating the adjustment, thereby permitting the operator to sawtapering lumber, such as l wheel-arms, wagon-tongues, fence-posts, andsuch other like tapering lumber. l

To enable those skilled in the art to make and use my improvedhead-block and carriage, I will proceedto -describe its construction andoperation.

Figure 1 of the drawings is a side elevation of the improved carriageand head-block.

Figure 2 is a plan of the same.

Figure 3 is an end elevation of it.

Figure 4 is a sectional elevation ofthe end of one of the head-blocks,showing an application of a brake to it.

A is the carriage, and in its generalconstruction is not unlike othercarriages used for similar purposes. The only improvement introduced inits construction is the plates a, which are securely fixed to its sidesat such intervals as the tail-block B will be likely to occupy whenchanged for diiferent lengths of logs. The plates a, as clearly shown iniig. 2, are simply lat metallic plates, having notches `cut in theirinner edges ofjust suicient size to receive the width of thehead-blocks. When the block B is to be placed on thc carriage it willjust be dropped into the notches thus prepared to receive it, and willthus be held securely in place on the carr riage. The head-blocks B Bare each of them provided with the sliding rests C of the usual form.The bottom edges ot' these rests are'provided with cogs7 as seen in iig.3. A pinion (not shown) in the central part of the head-block gears intoand actuates the said rests either forward or backward, asmay berequired. These pinions are located on the same shafts as thebevel-wheels D, and are actuated by them, and these wheels D are in turnactuated by the bevel-wheels Dl, which are located on the inner ends ofthe shafts DI", which have their bearings in the lugs ZJ, projectingfrom the sides of the head-blocks B B. There are levers E E iixed to theouter ends of the shafts D2, the positionsv of the said levers beingvertical, or nearly vertical, and their upper ends terminating in handlepieces e e, while their lower ends extend downward a few inches, say sixor eight, (more or less,) below theshafts D2, and are there providedwith wrists eZ ef. A horizontal connecting-bar, F, connects the twowrists e2 e3 together, as shown in iig. 1 of the drawings. One singlecircular orifice for the wrist e2 is provided in the saidconnecting-bar, but a number of slotsf are made in the bottom` of thesame for the reception of the wrist e3, the said slots f being disposedat intervals along the length of the said bar, the said intervals beingarranged to suit the different locations of the block B. As is clearlyshown in tig. 3, the lower ends of the leversE E arevdivided into twobranches, between which are placed the cogged pinions G G, and also theratchet-wheel g. The wheels Gr are securely xed to the axles or shaftsD2, and the wheels G and the ratchet g are placed-on independent axlesjust above them,the latter axles inding their bearings in the twobranches of the levers, and in such proximity to the shafts DL as toallow the cogs of G and G to gear into each other. There are doublepaw-ls I-I Il pivoted to the Outcrsides of the levers E E', as clearlyshown in iig. I. The upper parts of these pawls arc provided withhandles` 7L t, by means of which they may be thrown. y forward orbackward at pleasdre, so as to gear into the ratchets g. When the saidpawls are thrown into contact with the said ratchets on either side, andthe lever E or E is operated forward or backward, as the case may be,the Contact so formed between the said pawl and ratchet will lock thewheels g Gr', so they cannot revolve on their axes, and the wheel Gwillthereby be compelled to turn, and with it thegcaring D D, and thus thesliding-rests C will be actuated either forward or backward, as may bedesired. As each of the pawls H H may be thrown into gear with itsratchet, either forward or backward, or out of gear entirely, by placingthe handle k or h parallel with the lever E or E, and as such contact ofsaid pawls with their appropriate ratchets F and the forward andbackward motion ofthe levers E E will cause motion to the aforesaidsliding rests C, either forward or backward, and furthermore, as thebottoms of the levers E E are connected together by means of the bar F,it follows that the operating of one of' the levers E or El, when bothof the pawls are inv gear on the cor responding sides of theirrespective ratchets, will aetuate both of the slides C in harmony withnach other, and when only one of the said pawlsis in gear only one oftho said slides C will be set in motion. As the pawls may be readily sotin gear or out of gear by means of the hand-les 71, t, it is evidentthat this arrangement of head-blocks will be very convenient wheretapering stuit` is to be saw-eil, and the whole arrangement et' thegearing is so simple and eiicient as to present much superiority overother head-block gearing non' in use. A grad# uatod disk, I, is attachedto the outside of the lever E, and small pcrforations z' in itsperiphery mark the graduation points. Into these porforations a pin maybe inserted at any pointldcsired, and when the said pin so insertedstrikes the edge of the head-block it will stop the motion of themachinery, and the easy and rapid setting of the mill may be thusaccomplished with great accuracy. It is the intention to place theperforations z'in such relative positions to each other as to indicatequarter inches for the motion of the slide C. The thickness of thestuft` sawed may' thus be ganged with great accuracy. A lever, L,pivotefl to the end of either et the head-blocks, has a turned-up end,which entersan annular groove, Z, out in the inner fece of the wheel G,and by pressing the said lever to one side or the other a brake will beapplied to the said wheel. ,A cam, L', operated by a crank, Z, the saidcam beinr: pivoted to the end of the head-block in close proximity ftothe said lever, may be used for the purpose of applying the brake. i

One great advantage of the employment of the head-blocks of theforegoing description is in the facility that is aiforded ,formanufacturing lumber from springy logs', for by unshipping the pawl fromits ratchet at either end, and reversing the motion at the other endoi'the carriage, the log at that end may be drawn back with the slide,provided that the log has been properly dogged.

Having described my invention, what I claim, is-

1. The combination of the levers E E', pawls 7L z, spur-gearings G G',shafts D2,bei'elgeari1igs D Dl, and head-blocks C C, arranged inthemanner described.

2. I claim the lever L, the cam L', with its crank Z', and the wheel Gr,when combined and arranged in tiie manner and for the purpose set forth.

DARIUS PARKIIURST.

Witnesses:

M. RANDOLPH, C11/is. H. Borrar

